How It Works – PhotoModeler’s Coded Targets

How and When to use PhotoModeler's Automated Coded Target Methods

​PhotoModeler’s target detection and marking tools are used when highly accurate 3D XYZ points are needed at key locations. PhotoModeler automatically detects applied or projected targets and solves for an accurate set of 3D points representing each target center. Coded targets provide the additional ability to automatically reference targets between photos. The resulting points can be used for line, curve, and surface modeling, or measurement and export as needed.

While the examples below discuss 3D object measurement, coded targets are also used extensively in 2D and 2.5D cases such as template digitizing, and boat deck measurement.

Appropriate Subjects | Photography | Examples | Tools to Use | Other Resources

Appropriate subjects

The appropriate subjects for target detection projects are those with curved or complex surfaces that don’t have distinct feature points. Also good when the very highest point accuracy is required. PhotoModeler’s unique coded targets provide complete automation for many projects.


Apply targets to the object or scene, then take photos at convergent angles, covering the targeted area with suitable overlap. Separate the camera positions horizontally and vertically if possible, while ensuring targets are not photographed at too shallow an angle, as shown below:


Here are some examples using this technique - with a brief description, a sample photo, the camera positions, and the 3D model for each:

Sample Description

Sample Photo

Photography Layout

3D Result

  • Model Ferrari
  • 7 photos
  • Points, lines, curves, surfaces
  • Door measurement
  • 3 photos
  • Points, lines, dimensions
  • Ceiling fan hood
  • 4 photos
  • Shapes
  • Small instrument
  • 13 photos
  • Points, lines, curves, surfaces, textures
  • School building
  • 15 photos
  • Points, lines, surfaces, textures

tools to use

PhotoModeler tools used in these projects:

  • Point Marking – mark points on distinct features in multiple photos.
  • Referencing – reference marked points between photos to ‘tie’ them together.
  • Add lines, curves, surfaces and other entities to build your required level of detail in the 3D model.

other resources

Study these tutorials and tips for help with creating a PhotoModeler projects that are automated with Coded Targets: